“We found that somewhere under 1 percent of the deals are worthwhile,” Adam Burakowski, the website’s associate deals editor, told ABC News.

The staff at thewirecutter.com point out that top-rated items aren’t as likely to be discounted, and that price inflation can take place around the holidays to make discounts look bigger.

For instance, the Black Friday price of one Dyson vacuum that ABC News found was $299, but the the same vacuum was $80 less in August.

Televisions are a different story, though.

“In terms of products that give people some of the greatest discounts on Black Friday, and someone’s always looking out for, is TVs,” said Burakowski. “You can get good discounts on great TVs and great discounts on good TVs.”

Apple products also rarely go on sale but can be discounted on Black Friday by 10 to 15 percent.

Here are tips to help weed out the good deals from the bad from ABC News:

Research and read reviews in advance, then use a deal aggregator site like bfads.net. The site lets you search by item to find the lowest advertised price.

Use this website: camelcamelcamel.com. It’s a great tool to track price history over time. If you find a lower price in the past than what is being advertised, hold off. Odds are it will go back down in price sometime after Black Friday.

Check for Amazon lightning deals. Amazon says its holiday flash sales that come and go will be the lowest price on that item in the last 365 days guaranteed. But if you want alerts on those lightning deals, you need the Amazon app. Add if your desired item gets a price cut, you’ll get a notification on the app in real time.